Http Passthrough Pluggable Protocol for Firefox - http

Question

How can I make an http passthrough pluggable protocol for IE work in Firefox?
Alternatively, how to develop one for Firefox? Any examples would be appreciated.
Thanks.

Answer 1

On Firefox, if you would like to bypass a default behavior in a "pluggable" manner, you could write an NPAPI based plugin. Let's say that the documentation is thin on this subject... but to get you started, you could consult this.
With an NPAPI plugin, you have access to the whole OS and thus are free to expose any other resources to Firefox.

Answer 2

Write an XPCOM object that implements nsIObserver. Then create listener for http-on-modify-request and http-on-examine-response.
var myObj = new MyObserver(); //implements nsIObserver
var observerService = Components.classes["#mozilla.org/observer-service;1"].getService(Components.interfaces.nsIObserverService);
observerService.addObserver(myObj "http-on-modify-request", false);
observerService.addObserver(myObj, "http-on-examine-response", false);

Answer 3

Write an XPCOM object that implements nsIProtocolHandler. For example, you can access local images from web pages:
const Cu = Components.utils;
const Ci = Components.interfaces;
const Cm = Components.manager;
const Cc = Components.classes;
Cu.import("resource://gre/modules/XPCOMUtils.jsm");+
Cu.import("resource://gre/modules/FileUtils.jsm");
Cu.import("resource://gre/modules/NetUtil.jsm");
/***********************************************************
class definition
***********************************************************/
function sampleProtocol() {
// If you only need to access your component from JavaScript,
//uncomment the following line:
this.wrappedJSObject = this;
}
sampleProtocol.prototype = {
classDescription: "LocalFile sample protocol",
classID: Components.ID("{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}"),
contractID: "#mozilla.org/network/protocol;1?name=x-localfile",
QueryInterface: XPCOMUtils.generateQI([Ci.nsIProtocolHandler]),
//interface nsIProtocolHandler
allowPort :function(port, scheme)
{
if ((port == 80)&&(scheme == x-localfile)) {
return true;
}
else
{
return false;
}
},
newChannel: function(aURI)
{
// Just example. Implementation must parse aURI
var file = new FileUtils.File("D:\\temp\\getImage.jpg");
var uri = NetUtil.ioService.newFileURI(file);
var channel = NetUtil.ioService.newChannelFromURI(uri);
return channel;
},
newURI(aSpec, aOriginCharset, aBaseURI)
{
//URI looks like x-localfile://example.com/image1.jpg
var uri = Cc["#mozilla.org/network/simple-uri;1"].createInstance(Ci.nsIURI);
uri.spec = aSpec;
return uri;
},
scheme: "x-localfile",
defaultPort: 80,
protocolFlags: 76
};
var components = [sampleProtocol];
if ("generateNSGetFactory" in XPCOMUtils)
var NSGetFactory = XPCOMUtils.generateNSGetFactory(components); // Firefox 4.0 and higher
else
var NSGetModule = XPCOMUtils.generateNSGetModule(components); // Firefox 3.x
Be carefull! This approach can create vulnerability